Jotobo,
Until you (as a full member of Christ’s Church) are able to avail yourself of the Sacrament of Reconciliation, my suggestion to you would be this: familiarize yourself with the Act of Contrition (a Catholic prayer that is recited as one receives absolution from a priest) and use it to fervently express your sorrow whenever you fail in holiness.
There are several variations on the prayer; what follows is the version I use personally:
*Oh, my God! *
I am heartily sorry for having offended You because of Your just punishments, but mostly because I have offended You - my God - Who are All Good and deserving of all of my love. I firmly resolve - with the Help of Your Grace - to confess my sins, to do penance, to avoid the near occasion of sin, and not to sin anymore.
Amen.
The ‘near occasion of sin’ (in case you are unfamiliar with the term) refers to those situations in which you might find yourself tempted to sin beyond your strength to resist; an example of such might be one who routinely struggles with alcoholism meeting a friend at the local tavern. A Christian is of course bound to avoid such circumstances.
The key to real repentance is genuine remorse (i.e. recognition of the seriousness of one’s sin and its opposition to God’s Sovereign Goodness, NOT melodramatic wallowing in one’s failures) and a willing desire to return to holiness; regardless of the specific formula you use to express such sentiments to God, it is of utmost importance that you do so with sincerity. Read Psalm 51; there you will find the essence of true contrition.
The Lord knows your heart; trust in His Mercy and Love and let Grace do the rest!
